Scientists at Tokyo University of Agriculture and Technology have developed a flicker-free solid-state cathode-ray tube that supports large, flat-screen devices. Unlike conventional cathode-ray tubes, which require bulky housing and which shoot electrons from hot cathode rays at a phosphor screen, the solid-state devices transmit electrons ballistically (in straight lines) through a cascade of porous silicon nanocrystallites. Also, electrons moving perpendicular to the device surface strike linear arrays of phosphor pixels, thus producing planar emission of light.According to the scientists, cold cathode-ray-tube technology eliminates image distortion, bright spots and local fluctuations in the image. The device also offers low power consumption and high resolution. The group described its work in the Sept. 23 issue of Applied Physics Letters.